System not booting properly

Have you had/heard of situations where Inteset thinks that S.L. is already running?  Or where it attempts to load twice?  It is inconsistent on when this occurs.

What happens is the screen/kiosk freezes at the Windows splash screen - and nothing happens (since everything is locked down, but the Master Application does not load)

I find this in the Windows Application log:

Another instance of Secure Lockdown is already running. Only one instance is allowed.

There isn't a whole lot of information to go on, since this is locked down.  There isn't a lot happening.  In fact, it is surprising that it is inconsistent, since there are so few moving pieces to this.  I've seen instances where a machine was rebooted a 2nd or 3rd time and everything worked fine.  Then, today, I rebooted maybe 5 times in a row and still the kiosk remained frozen.  

Any hints of where to look would be appreciated.

Be sure you're using the latest release of Secure Lockdown. The Windows Task Scheduler is used to launch Secure Lockdown upon startup. It is highly unlikely that it is starting it twice. Be sure you're not starting it via any other method (ie: the Windows Startup folder, Windows Registry "Run" key, etc.)